1. Field of Invention
The present invention relates to nuclear techniques for detecting impurities such as salt water and sulfur in petroleum refining and producing operations.
2. Description of Prior Art
U.S. Pat. No. 4,209,695 dated June 24, 1980, of common ownership to the present application, relates to a nuclear technique for measuring the chlorine and sulfur content of a flowing stream of fluid. However, the technique of this patent required that any free gas in the fluid be homogeneously mixed. Otherwise, any free gas in the stream of fluid introduced errors in the chlorine (and thus salt content) and sulfur measurements by varying the relative shielding properties of the fluid. Thus, for accurate results apparatus of the type in that patent was typically at the output of a gas-oil separator. There are, however, other locations in petroleum producing or refining operations where gas is present in the fluid and it is desirable to monitor the salt content of the fluid.
U.S. Pat. No. 4,200,789, dated Apr. 29, 1980 also of common ownership to the present application, relates to a technique for measuring oil and water cuts of a multiphase flowstream. The flowstream was bombarded with neutrons and high energy gamma rays resulting from the capture of thermal neutrons was detected. The spectra of the detected gamma rays were analyzed and the gamma ray counts of the element sulfur and the element chlorine determined. Since the gamma ray spectra of the element hydrogen was not needed or used, the effects of gas in the stream on oil and water cut measurements were eliminated.